cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A112573 G.f. A(x) satisfies: A(x)^3 equals the g.f. of A110640, which consists entirely of numbers 1 through 9.

Original entry on oeis.org

1, 1, 0, 0, 2, -2, 5, -6, 5, 3, -26, 70, -141, 221, -229, -18, 891, -2914, 6524, -11238, 13690, -4214, -37619, 145018, -353534, 657080, -895234, 534007, 1654246, -7840402, 20737566, -41200153, 61402057, -50500722, -68352913, 441195837, -1272153666, 2690651374
Offset: 0

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Author

Paul D. Hanna, Sep 14 2005

Keywords

Comments

A110640 is formed from every third term of A083949, which also consists entirely of numbers 1 through 9.

Examples

			A(x) = 1 + x + 2*x^4 - 2*x^5 + 5*x^6 - 6*x^7 + 5*x^8 + 3*x^9 +...
A(x)^3 = 1 + 3*x + 3*x^2 + x^3 + 6*x^4 + 6*x^5 + 9*x^6 + 6*x^7 +...
A(x)^9 = 1 + 9*x + 36*x^2 + 84*x^3 + 144*x^4 + 252*x^5 + 489*x^6 +..
A(x)^9 (mod 27) = 1 + 9*x + 9*x^2 + 3*x^3 + 9*x^4 + 9*x^5 + 3*x^6+..
G(x) = 1 + 9*x + 9*x^2 + 3*x^3 + 9*x^4 + 9*x^5 + 3*x^6 + 9*x^7 +...
where G(x) is the g.f. of A083949.
		

Crossrefs

Programs

  • PARI
    {a(n)=local(d=3,m=9,A=1+m*x); for(j=2,d*n, for(k=1,m,t=polcoeff((A+k*x^j+x*O(x^j))^(1/m),j); if(denominator(t)==1,A=A+k*x^j;break))); polcoeff(Ser(vector(n+1,i,polcoeff(A,d*(i-1))))^(1/3),n)}

Formula

G.f. A(x) satisfies: A(x)^9 (mod 27) = g.f. of A083949.

A110639 Every 9th term of A083949 where the self-convolution 9th power is congruent modulo 27 to A083949, which consists entirely of numbers 1 through 9.

Original entry on oeis.org

1, 1, 9, 9, 2, 7, 5, 3, 5, 3, 1, 7, 3, 5, 5, 9, 9, 2, 8, 3, 1, 7, 1, 1, 4, 8, 5, 1, 1, 2, 9, 2, 7, 6, 8, 6, 6, 7, 2, 2, 5, 6, 5, 9, 6, 1, 6, 7, 4, 5, 6, 4, 9, 8, 4, 1, 4, 9, 9, 2, 3, 1, 9, 4, 2, 6, 6, 8, 2, 5, 3, 2, 5, 2, 8, 2, 4, 6, 4, 8, 6, 2, 5, 2, 8, 9, 8, 1, 2, 3, 3, 2, 9, 1, 1, 1, 4, 8, 5, 5, 7, 8, 7, 3, 1
Offset: 0

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Author

Keywords

Examples

			A(x) = 1 + x + 9*x^2 + 9*x^3 + 2*x^4 + 7*x^5 + 5*x^6 +...
A(x)^9 = 1 + 9*x + 117*x^2 + 813*x^3 + 5976*x^4 + 33381*x^5 +...
A(x)^9 (mod 27) = 1 + 9*x + 9*x^2 + 3*x^3 + 9*x^4 + 9*x^5 +...
G(x) = 1 + 9*x + 9*x^2 + 3*x^3 + 9*x^4 + 9*x^5 + 3*x^6 +...
where G(x) is the g.f. of A083949.
		

Crossrefs

Programs

  • PARI
    {a(n)=local(d=9,m=9,A=1+m*x); for(j=2,d*n, for(k=1,m,t=polcoeff((A+k*x^j+x*O(x^j))^(1/m),j); if(denominator(t)==1,A=A+k*x^j;break)));polcoeff(A,d*n)}
Showing 1-2 of 2 results.